This invention relates generally an overfeed (or “pre-take-up”) roller assembly, textile machine, and method of adjusting tension in a running yarn being wound by a take-up mechanism. The exemplary assemblies and methods described herein may be utilized to obtain a relatively soft wound package in a thread-processing machine, such as a two-for-one twister (also referred to as a “double twister” or “yarn cabler”).
In a conventional two-for-one twister, a yarn coming from a double twisting spindle ordinarily has a high tension increased by ballooning. Accordingly, an overfeed feed roller is arranged between the double twisting spindle and a take-up roller to overfeed the yarn and reduce the yarn tension, and the yarn having a reduced tension is passed through a traverse device and wound on a rotating package by the take-up roller. In forming wound packages by such double twister, especially in case of processed yarns, the tension given by ballooning must be sufficiently reduced by the overfeed roller in order to obtain a softer wound package, and the resulting soft wound package may then be fed to a subsequent textile process, such as heat-setting.
In exemplary embodiments described below, the present invention comprises an improved overfeed roller assembly designed to adjust the tractive force and tension on a running thread being wound by a take-up mechanism in a thread processing machine, such as a two-for-one twister, and positioned in the machine in advance of the take-up mechanism in the running thread path. The present overfeed roller assembly may comprise multiple pieces (e.g., two identical semi-circular halves) designed for ready and convenient assembly and disassembly on a variably driven rotating drive shaft carried by the machine.